use event to override vote on task

Now, the bundle dispatch an event `chill_task.vote` to override the authorization
on voting on a task.

If a subscriber or listener emits a vote on the event, this vote override the
logic defined for the default task.

Security/Authorization/TaskVoter.php

@@ -29,6 +29,8 @@ use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
 use Chill\MainBundle\Entity\User;
 use Chill\PersonBundle\Entity\Person;
 use Symfony\Component\Security\Core\Role\Role;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Chill\TaskBundle\Security\Authorization\AuthorizationEvent;
 
 /**
  *
@@ -66,14 +68,22 @@ class TaskVoter extends AbstractChillVoter implements ProvideRoleHierarchyInterf
      * @var LoggerInterface
      */
     protected $logger;
+    
+    /**
+     *
+     * @var EventDispatcherInterface
+     */
+    protected $eventDispatcher;
 
     public function __construct(
         AccessDecisionManagerInterface $accessDecisionManager,
         AuthorizationHelper $authorizationHelper,
+        EventDispatcherInterface $eventDispatcher,
         LoggerInterface $logger
     ) {
         $this->accessDecisionManager = $accessDecisionManager;
         $this->authorizationHelper = $authorizationHelper;
+        $this->eventDispatcher = $eventDispatcher;
         $this->logger = $logger;
     }
 
@@ -101,6 +111,21 @@ class TaskVoter extends AbstractChillVoter implements ProvideRoleHierarchyInterf
         if (!$token->getUser() instanceof User) {
             return false;
         }
+        
+        $event = new AuthorizationEvent($subject, $attribute, $token);
+        
+        $this->eventDispatcher->dispatch(AuthorizationEvent::VOTE, $event);
+        
+        if ($event->hasVote()) {
+            
+            $this->logger->debug("The TaskVoter is overriding by "
+                .AuthorizationEvent::VOTE, [
+                    'vote' => $event->getVote(),
+                    'task_id' => $subject->getId()
+                ]);
+            
+            return $event->getVote();
+        }
 
         if ($subject instanceof AbstractTask) {
             if ($subject->getPerson() === null) {